Institute for Systems Research Technical Reports

Permanent URI for this collectionhttp://hdl.handle.net/1903/4376

This archive contains a collection of reports generated by the faculty and students of the Institute for Systems Research (ISR), a permanent, interdisciplinary research unit in the A. James Clark School of Engineering at the University of Maryland. ISR-based projects are conducted through partnerships with industry and government, bringing together faculty and students from multiple academic departments and colleges across the university.

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Author: search.filters.author.Roy-Chowdhury, Ayan

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    Study of OLSR for Real-time Media Streaming over 802.11 Wireless Network in Software Emulation Environment
    (2010-07) Jain, Kaustubh; Somasundaram, Kiran; Wang, Brian; Baras, John; Roy-Chowdhury, Ayan
    In this paper we present a setup to study the real-time traffic carrying performance of optimized Link State Routing (OLSR) protocol using software emulation. We emulate the IEEE 802.11 MAC/PHY using the EMANE software emulator, on a cluster of machines, for different multi-hop wireless scenarios. As an instance of real-world usage scenario, we study the performance of real-time streaming media over a mesh network supported by OLSR. In particular, we study the effect of mobility and background traffic on carried load and jitter. We propose to extend this emulation setup to test the real-time performance of prototype routing protocols such as Stable Path Topology Control (SPTC) and other real-time applications.
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    HYBRID NETWORKS WITH A SPACE SEGMENT - TOPOLOGY DESIGN AND SECURITY ISSUES
    (2005) Roy-Chowdhury, Ayan; Baras, John S.; Hadjitheodosiou, Michael H.; Rentz, Nicolas; Baras, Dr. John S.; ISR; CSHCN
    In this paper we investigate a hybrid network topology that is suitable for supporting interplanetary communications. We define an architecture comprised of a network of sensor nodes on a remote planetary surface, connected to a hybrid terrestrial network of wired and wireless LANs through a series of satellite relays. All the nodes in the network are IPaddressable and support public and symmetric key cryptography. The resulting network forms a hierarchical hybrid mesh that connects users on Earth to networks on or around a remote planetary surface. We describe the design of the network and present preliminary simulation results illustrating the network performance for various parameters. We also discuss how algorithms for user authentication, message integrity and data confidentiality can be incorporated in the network infrastructure for secure end-to-end communication.
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    A Certificate-based Light-weight Authentication Algorithm For Resource-constrained Devices
    (2005) Roy-Chowdhury, Ayan; Baras, John S.; Baras, John S.; ISR; CSHCN
    In this work, we analyze and extend a recently proposed design of digital certificates called TESLA certificates. Certificates are a necessary tool in today's secure networks to certify the identity of nodes taking part in communication. Most prevalent certificate technologies make use of public-key cryptography. Messages generated by the user are signed using its private key, and the signature can be verified by any node who knows the user's public key via its certificate. Signature generation and verification using public-key cryptography is computationally expensive for devices with limited computation power and energy resources. In this situation TESLA certificates can be very useful to certify identity, since they rely on symmetric cryptography which is computationally much more efficient. In this paper we explain the concept of TESLA certificates and provide a preliminary description of proposed modifications to the original algorithm to strengthen its security. We extend the original proposal by combining hash chains with TESLA certificates and come up with an efficient source and message authentication protocol based on symmetric key certificates. We also propose a new type of TESLA certificates called Group Certificates for use in multicast group communication. Through analysis, we show that our protocol is secure against malicious adversaries. We also give an initial estimate of the performance of our algorithm and the related comparison to public-key signatures, and we highlight network scenarios where the TESLA certificates could be particularly useful.
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    Security Issues in Hybrid Satellite Networks
    (2004) Roy-Chowdhury, Ayan; Hadjitheodosiou, Michael H.; Baras, John S.; Baras, John S.; ISR; CSHCN
    Satellites are expected to play an increasingly important role in providing broadband Internet services over long distances in an efficient manner. Future networks will be hybrid in nature - having terrestrial nodes interconnected by satellite links. Security is an important concern in such networks, since the satellite segment is susceptible to a host of attacks including eavesdropping, session hijacking and data corruption. In this paper we address the issue of securing communication in satellite networks. We describe the different kinds of hybrid network topologies considered for deployment. We discuss various security attacks that are possible in these networks, and survey the different solutions proposed to secure communications in the hybrid networks. We point out important drawbacks in the various proposed solutions, and suggest a hierarchical approach to add security to the hybrid networks.
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    Framework for IP Multicast in Satellite ATM Networks
    (2004) Roy-Chowdhury, Ayan; Baras, John S.; Baras, John S.; ISR; CSHCN
    This paper proposes a design for IP multicast routing in hybrid satellite networks. The emergence of IP multicast for Internet group communication has placed focus on communication satellites as an efficient way to extend IP multicast services for groups with distributed membership in wide-area networks. This poses interesting challenges for routing. Satellite networks can have both wired and wireless links and also combine different link-layer technologies like Ethernet and ATM. No proposed IP multicast routing protocol for wired networks offers an integrated solution for such networks. This paper attempts to provide a solution by proposing a design for IP multicast routing in wide-area networks that have terrestrial Ethernet LANs interconnected by ATM-based satellite channels. The paper reviews the multicast services offered by IP and ATM, and proposes a multicast routing framework that combines PIM-SM protocol for terrestrial multicasting with the ATM MARS and VC mesh architecture for multicast routing over the satellite links. Modifications are made to the standard protocols to suit the unique needs of the network being considered. The feasibility of the proposed design is tested by performing simulations. The proposed framework is presented in detail, along with analysis and simulation results.
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    Key Management for Secure Multicast in Hybrid Satellite Networks
    (2004) Roy-Chowdhury, Ayan; Baras, John S.; Baras, John S.; ISR; CSHCN
    This paper proposes a design for key management for secure multicast in hybrid satellite networks. Communication satellites offer an efficient way to extend IP multicast services for groups in wide-area networks. In order to be commercially viable, the multicast traffic should be accessible only to paying subscribers. Access control can be achieved by data encryption. This requires secure and efficient methods to generate, distribute and update the keys. Most current key management protocols do not scale well when applied to large dynamic groups in wide-area networks. This paper attempts to solve the above problem for groups in a hybrid network that is composed of terrestrial Ethernet LANs interconnected by ATM-based satellite channels. We investigate current group key management protocols, and design a framework for secure and scalable key management for the multicast routing architecture in the satellite network. The proposed framework is presented in detail, alongwith analysis and simulation results.
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    IP Routing and Key Management for Secure Multicast in Satellite ATM Networks
    (2004) Roy-Chowdhury, Ayan; Baras, Dr. John S.; ISR; CSHCN
    This thesis proposes a design for secure IP multicast in hybrid satellite networks. The emergence of IP multicast for Internet group communication has placed focus on communication satellites as an efficient way to extend the IP multicast services for groups with distributed membership in wide-area networks. This poses interesting challenges for routing and security. Satellite networks can have both wired and wireless links and also different link-layer technologies like Ethernet and ATM. No proposed IP multicast routing protocol for wired networks offers an integrated solution for such networks. From the security viewpoint, in order to be commercially viable, the multicast traffic should be accessible only to legitimate receivers. Access control can be achieved by data encryption, with the correct decryption keys provided to authorized members. This requires secure and efficient methods to generate, distribute and update the keys. Most current key management protocols do not scale well when applied to large dynamic groups operating in wide-area networks. This thesis attempts to solve the above problems and proposes a design for secure multicast in wide-area networks that have terrestrial Ethernet LANs interconnected by ATM-based satellite channels. The thesis reviews the multicast services offered by IP and ATM, and proposes a multicast routing framework for hybrid satellite networks. The thesis also investigates current group key management protocols, and designs a scheme for secure and scalable key management for the proposed multicast routing architecture. The various proposed schemes are presented in detail, alongwith analysis and simulation results.